java.lang.OutOfMemoryError how to fix this

Question

i found a code but sometimes have error :

StringBuilder strHeaders = new StringBuilder();
char c;
while ((c = (char)stream.read()) != -1) {
    strHeaders.append(c);
    if (strHeaders.length() > 5 && (strHeaders.substring((strHeaders.length() - 4), strHeaders.length()).equals("\r\n\r\n"))) {
        // end of headers
        break;
    }
}

logcat

java.lang.OutOfMemoryError
    at java.lang.AbstractStringBuilder.enlargeBuffer(AbstractStringBuilder.java:95)
    at java.lang.AbstractStringBuilder.append0(AbstractStringBuilder.java:140)
    at java.lang.StringBuilder.append(StringBuilder.java:125)
    at myApp.activity.com.getFromPLS.retreiveMetadata(getFromPLS.java:98)
    at myApp.activity.com.getFromPLS.refreshMeta(getFromPLS.java:76)
    at myApp.activity.com.myApp$1.run(myApp.java:371)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:130)
    at android.app.ActivityThread.main(ActivityThread.java:3683)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
    at dalvik.system.NativeStart.main(Native Method)

error on this line

strHeaders.append(c);

please any one can help me to fix this ?

Ted Hopp · Accepted Answer · 2012-01-22T10:49:55.807

Since char is an unsigned type, your while loop condition will never be satisfied, even after stream.read() starts returning -1. If you don't find a "\r\n\r\n" sequence, the loop will never end. Write the loop like this:

StringBuilder strHeaders = new StringBuilder();
int c;
while ((c = stream.read()) != -1) { // DO NOT cast to char here!
    strHeaders.append((char) c);
    final int len = strHeaders.length();
    if (len > 5 && (strHeaders.substring(len - 4)).equals("\r\n\r\n"))) {
        // end of headers
        break;
    }
}

Note that many servers will incorrectly return "\n\n" as the blank line that signals the end of the header. Some may also return "\r\r". Unless you control the server output and are guaranteed that it will see "\r\n\r\n", your blank-line detection method needs to be written in a more robust manner.

score 0 · Answer 2 · answered Jan 22 '12 at 10:43

This has more to do with the file you are reading. If the file size is large then you will landing into this issue. The best bet will be keep a check on the file size and pipe it to smaller chunks. The more you put data in StringBuffer the more loaded your memory will be.

java.lang.OutOfMemoryError how to fix this

2 Answers2